795纳米单模半导体激光器作为铷原子的泵浦源，在芯片级的原子钟、原子陀螺仪、原子磁强计等方面具有非常重要的应用。传统实现这种激光器的方案包括垂直腔面发射激光器和边发射分布反馈激光器。本项目提出了一种新的基于表面光栅的分布反馈激光器方案，该方案能提供高耦合系数的表面光栅（耦合系数预计达到800 1/cm），因此能使用约50微米短腔长（增益区的长度）。本项目将开展激光器的理论设计，研究器件制备工艺，并在实验上展示出激光器，预期性能达到：阈值小于0.5毫安，斜率效率高于0.5毫瓦/毫安，边模抑制比高于40dB，线宽小于10MHz，相对强度噪声低于-140dB/Hz。该激光器方案具备传统分布反馈激光器的优点如稳定TE偏振、高边模抑制比、窄线宽、精准波长控制，同时具备垂直腔面发射激光器的优点如低阈值低功耗、制作过程不需要二次外延，因而将在芯片级的原子钟或其它芯片级的原子传感器方面具有重要应用。

795nm single mode semiconductor lasers as the pumping sources for Rubidium, have very important applications in chip-scale atomic clock, atomic gyroscope, and atomic magnetometer, etc. Traditional methods to realize this type of lasers include vertical-cavity surface-emitting lasers (VCSEL) and edge-emitting distributed feedback lasers (DFB). This application proposes a new type of DFB lasers based on surface gratings. The surface gratings can have high coupling coefficients (coupling coefficient expected to reach 800 1/cm), so that the laser can use a short cavity length (gain section length) approximately 50 mirometer long. This project will focus on the design and fabrication of the proposed laser and is expected to domonstrate the following laser characteristics: threshold-current <0.5mA, output slope-efficiency >0.5mW/mA, side-mode suppression-ratio >40dB, linewidth <10MHz, and relative-intensity-noise<-140dB/Hz. The proposed laser has the merits of traditional DFB lasers such as stable TE polarization for the output, high side-mode suppression-ratio, narrow linewidth, accurate wavelength control. It also has the merits of VCSELs such as low threshold and low power consumption, fabrication without the need for regrowth. Therefore, it is expected to have important applications in chip-scale atomic clocks and other chip-scale atomic sensors.